Spectrum Management and Telecommunications

RIC-8 - Advanced Qualification Question Bank for Amateur Radio Operator Certificate

A-005-01-01 (1)
How is the positive feedback coupled to the input in a Hartley oscillator?

Through a tapped coil
Through a capacitive divider
Through link coupling
Through a neutralizing capacitor

A-005-01-02 (4)
How is positive feedback coupled to the input in a Colpitts oscillator?

Through a tapped coil
Through a neutralizing capacitor
Through a link coupling
Through a capacitive divider

A-005-01-03 (3)
How is positive feedback coupled to the input in a Pierce oscillator?

Through a neutralizing capacitor
Through link coupling
Through capacitive coupling
Through a tapped coil

A-005-01-04 (2)
Why is the Colpitts oscillator circuit commonly used in a VFO?

It can be used with or without crystal lock-in
It is stable
The frequency is a linear function with load impedance
It has high output power

A-005-01-05 (2)
Why must a very stable reference oscillator be used as part of a phaselocked loop (PLL) frequency synthesizer?

Any phase variations in the reference oscillator signal will produce harmonic distortion in the modulating signal
Any phase variations in the reference oscillator signal will produce phase noise in the synthesizer output
Any amplitude variations in the reference oscillator signal will prevent the loop from changing frequency
Any amplitude variations in the reference oscillator signal will prevent the loop from locking to the desired signal

A-005-01-06 (4)
Positive feedback from a capacitive divider indicates the oscillator type is:

Pierce
Hartley
Miller
Colpitts

A-005-01-07 (4)
In an oscillator circuit designed for high stability, the positive feedback is drawn from two capacitors connected in series. These two capacitors would most likely be:

ceramic
electrolytics
mylar
silver mica

A-005-01-08 (4)
In an oscillator circuit where positive feedback is obtained through a single capacitor in series with the crystal, the type of oscillator is:

Colpitts
Hartley
Miller
Pierce

A-005-01-09 (3)
A circuit depending on positive feedback for its operation would be a:

mixer
detector
variable-frequency oscillator
audio amplifier

A-005-01-10 (1)
An apparatus with an oscillator and a class C amplifier would be:

a two-stage CW transmitter
a fixed-frequency single-sideband transmitter
a two-stage frequency-modulated transmitter
a two-stage regenerative receiver

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A-005-01-11 (4)
In an oscillator where positive feedback is provided through a capacitor in series with a crystal, that type of oscillator is a:

Colpitts
Hartley
Franklin
Pierce

A-005-02-01 (2)
The output tuning controls on a transmitter power amplifier:

allow switching to different antennas
allow efficient transfer of power to the antenna
reduce the possibility of crossmodulation in adjunct receivers
are involved with frequency multiplication in the previous stage

A-005-02-02 (1)
The purpose of using a centre-tap return connection on the secondary of transmitting tube's filament transformer is to:

prevent modulation of the emitted wave by the alternating current filament supply
reduce the possibility of harmonic emissions
keep the output voltage constant with a varying load
obtain optimum power output

A-005-02-03 (1)
In a grounded grid amplifier using a triode vacuum tube, the input signal is applied to:

the cathode
the plate
the control grid
the filaments

A-005-02-04 (4)
In a grounded grid amplifier using a triode vacuum tube, the plate is connected to the pi-network through a:

by-pass capacitor
tuning capacitor
electrolytic capacitor
blocking capacitor

A-005-02-05 (2)
In a grounded grid amplifier using a triode vacuum tube, the plate is connected to a radio frequency choke. The other end of the radio frequency choke connects to the:

filament voltage
B+ (high voltage)
ground
B- (bias)

A-005-02-06 (3)
In a grounded grid amplifier using a triode vacuum tube, the cathode is connected to a radio frequency choke. The other end of the radio frequency choke connects to the:

ground
filament voltage
B- (bias)
B+ (high voltage)

A-005-02-07 (4)
In a grounded grid amplifier using a triode vacuum tube, the secondary winding of a transformer is connected directly to the vacuum tube. This transformer provides:

B- (bias)
B+ (high voltage)
Screen voltage
filament voltage

A-005-02-08 (2)
In a grounded grid amplifier using a triode vacuum tube, what would be the approximate B+ voltage required for an output of 400 watts at 400 mA with approximately 50 percent efficiency?

500 volts
2000 volts
3000 volts
1000 volts

A-005-02-09 (2)
In a grounded grid amplifier using a triode vacuum tube, each side of the filament is connected to a capacitor whose other end is connected to ground. These are:

tuning capacitors
by-pass capacitors
electrolytic capacitors
blocking capacitors

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A-005-02-10 (2)
After you have opened a VHF power amplifier to make internal tuning adjustments, what should you do before you turn the amplifier on?

Make sure that the power interlock switch is bypassed so you can test the amplifier
Be certain all amplifier shielding is fastened in place
Be certain no antenna is attached so that you will not cause any interference
Remove all amplifier shielding to ensure maximum cooling

A-005-02-11 (3)
Harmonics produced in an early stage of a transmitter may be reduced in a later stage by :

larger value coupling capacitors
greater input to the final stage
tuned circuit coupling between stages
transistors instead of tubes

A-005-03-01 (2)
In a simple 2 stage CW transmitter circuit, the oscillator stage and the class C amplifier stage are inductively coupled by a RF transformer. Another role of the RF transformer is to:

act as part of a pi filter
be part of a tuned circuit
provide the necessary feedback for oscillation
act as part of a balanced mixer

A-005-03-02 (2)
In a simple 2 stage CW transmitter, current to the collector of the transistor in the class C amplifier stage flows through a radio frequency choke (RFC) and a tapped inductor. The RFC, on the tapped inductor side, is also connected to grounded capacitors. The purpose of the RFC and capacitors is to:

provide negative feedback
form a low-pass filter
form a key-click filter
form a RF-tuned circuit

A-005-03-03 (3)
In a simple 2 stage CW transmitter, the transistor in the second stage would act as:

a frequency multiplier
the master oscillator
a power amplifier
an audio oscillator

A-005-03-04 (2)
An advantage of keying the buffer stage in a transmitter is that:

key clicks are eliminated
changes in oscillator frequency are less likely
the radiated bandwidth is restricted
high RF voltages are not present

A-005-03-05 (2)
As a power amplifier is tuned, what reading on its grid-current meter indicates the best neutralization?

Minimum grid current
A minimum change in grid current as the output circuit is changed
Maximum grid current
A maximum change in grid current as the output circuit is changed

A-005-03-06 (2)
What does a neutralizing circuit do in an RF amplifier?

It eliminates AC hum from the power supply
It cancels the effects of positive feedback
It reduces incidental grid modulation
It controls differential gain

A-005-03-07 (4)
What is the reason for neutralizing the final amplifier stage of a transmitter?

To limit the modulation index
To cut off the final amplifier during standby periods
To keep the carrier on frequency
To eliminate self-oscillations

A-005-03-08 (3)
Parasitic oscillations are usually generated due to:

harmonics from some earlier multiplier stage
excessive drive or excitation to the power amplifier
accidental resonant frequencies in the power amplifier
a mismatch between power amplifier and feedline

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A-005-03-09 (4)
Parasitic oscillations would tend to occur mostly in:

high gain audio output stages
high voltage rectifiers
mixer stages
RF power output stages

A-005-03-10 (2)
Why is neutralization necessary for some vacuum-tube amplifiers?

To reduce grid-to-cathode leakage
To cancel oscillation caused by the effects of interelectrode capacitance
To cancel AC hum from the filament transformer
To reduce the limits of loaded Q

A-005-03-11 (3)
Parasitic oscillations in an RF power amplifier may be caused by:

overdriven stages
unintended tuned circuits
lack of neutralisation
excessive harmonic production

A-005-04-01 (2)
What type of signal does a balanced modulator produce?

FM with balanced deviation
Double sideband, suppressed carrier
Full carrier
Single sideband, suppressed carrier

A-005-04-02 (3)
How can a single-sideband phone signal be produced?

By driving a product detector with a DSB signal
By using a loop modulator followed by a mixer
By using a balanced modulator followed by a filter
By using a reactance modulator followed by a mixer

A-005-04-03 (2)
Carrier suppression in a single-sideband transmitter takes place in:

the carrier decouple stage
the balanced modulator stage
the mechanical filter
the frequency multiplier stage

A-005-04-04 (2)
Transmission with SSB, as compared to conventional AM transmission, results in:

6 dB gain in the receiver
6 dB gain in the transmitter and 3 dB gain in the receiver
a greater bandpass requirement in the receiver
3 db gain in the transmitter

A-005-04-05 (3)
The peak power output of a singlesideband transmitter, when being tested by a two-tone generator is:

equal to the RF peak output power of any of the tones
one-half of the RF peak output power of any of the tones
twice the RF power output of any of the tones
one-quarter of the RF peak output power of any of the tones

A-005-04-06 (2)
What kind of input signal is used to test the amplitude linearity of a singlesideband phone transmitter while viewing the output on an oscilloscope?

An audio-frequency sine wave
Two audio-frequency sine waves
An audio-frequency square wave
Normal speech

A-005-04-07 (1)
When testing the amplitude linearity of a single-sideband microphone input and on what audio tones are fed into the transmitter, what kind of kind of instrument is the output observed?

Two non-harmonically related tones are fed in, and the output is observed on an oscilloscope
Two harmonically related tones are fed in, and the output is observed on an oscilloscope
Two harmonically related tones are fed in, and the output is observed on a distortion analyzer
Two non-harmonically related tones are fed in, and the output is observed on a distortion analyzer

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A-005-04-08 (4)
What audio frequencies are used in a two-tone test of the linearity of a singlesideband phone transmitter?

20 Hz and 20 kHz tones must be used
1200 Hz and 2400 Hz tones must be used
Any two audio tones may be used, but they must be within the transmitter audio passband, and must be harmonically related
Any two audio tones may be used, but they must be within the transmitter audio passband, and should not be harmonically related

A-005-04-09 (3)
What measurement can be made of a single-sideband phone transmitter's amplifier by performing a two-tone test using an oscilloscope?

Its frequency deviation
Its percent of carrier phase shift
Its linearity
Its percent of frequency modulation

A-005-04-10 (1)
How much is the carrier suppressed below peak output power in a singlesideband phone transmission?

At least 40 dB
No more than 20 dB
No more than 30 dB
At least 60 dB

A-005-04-11 (1)
What is meant by flattopping in a singlesideband phone transmission?

Signal distortion caused by excessive drive
Signal distortion caused by insufficient collector current
The transmitter's automatic level control is properly adjusted
The transmitter's carrier is properly suppressed

A-005-05-01 (1)
In an FM phone signal having a maximum frequency deviation of 3000 Hz either side of the carrier frequency, what is the modulation index, when the modulating frequency is 1000 Hz?

3
0.3
3000
1000

A-005-05-02 (3)
What is the modulation index of an FM phone transmitter producing an instantaneous carrier deviation of 6 kHz when modulated with a 2 kHz modulating frequency?

0.333
2000
3
6000

A-005-05-03 (4)
What is the deviation ratio of an FM phone signal having a maximum frequency swing of plus or minus 5 kHz and accepting a maximum modulation rate of 3 kHz?

60
0.16
0.6
1.66

A-005-05-04 (2)
What is the deviation ratio of an FM phone signal having a maximum frequency swing of plus or minus 7.5 kHz and accepting a maximum modulation rate of 3.5 kHz?

0.47
2.14
47
0.214

A-005-05-05 (4)
When the transmitter is not modulated, or the amplitude of the modulating signal is zero, the frequency of the carrier is called its:

frequency deviation
frequency shift
modulating frequency
centre frequency

A-005-05-06 (1)
In a FM transmitter system, the number of cycles of deviation from the centre frequency is determined solely by the:

amplitude of the modulating frequency
frequency of the modulating frequency
amplitude and the frequency of the modulating frequency
modulating frequency and the amplitude of the centre frequency

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A-005-05-07 (4)
Any FM wave with single-tone modulation has:

two sideband frequencies
four sideband frequencies
one sideband frequency
an infinite number of sideband frequencies

A-005-05-08 (3)
The deviation meter works on the principle of:

detecting the frequencies in the sidebands
the amplitude of power in the sidebands
a carrier null and multiplying the modulation frequency by the modulation index
a carrier peak and dividing by the modulation index

A-005-05-09 (1)
When using a deviation meter, it is important to know:

modulating frequency and the modulation index
modulation index
modulating frequency
pass-band of the IF filter

A-005-05-10 (3)
What is the total bandwidth of an FM phone transmission having a 5-kHz deviation and a 3-kHz modulating frequency?

8 kHz
5 kHz
16 kHz
3 kHz

A-005-05-11 (3)
What is the frequency deviation for a 12.21-MHz reactance-modulated oscillator in a 5-kHz deviation, 146.52-MHz FM-phone transmitter?

12 kHz
5 kHz
416.7 Hz
41.67 Hz

A-005-06-01 (2)
If the signals of two repeater transmitters mix together in one or both of their final amplifiers and unwanted signals at the sum and difference frequencies of the original signals are generated, what is this called?

Neutralization
Intermodulation interference
Adjacent channel interference
Amplifier desensitization

A-005-06-02 (3)
How does intermodulation interference between two repeater transmitters usually occur?

When the signals are reflected in phase by aircraft passing overhead
When they are in close proximity and the signals cause feedback in one or both of their final amplifiers
When they are in close proximity and the signals mix in one or both of their final amplifiers
When the signals are reflected out of phase by aircraft passing overhead

A-005-06-03 (3)
How can intermodulation interference between two repeater transmitters in close proximity often be reduced or eliminated?

By installing a low-pass filter in the antenna feed line
By installing a high-pass filter in the antenna feed line
By installing a terminated circulator or ferrite isolator in the feed line to the transmitter and duplexer
By using a Class C final amplifier with high driving power

A-005-06-04 (4)
If a receiver tuned to 146.70 MHz receives an intermodulation product signal whenever a nearby transmitter transmits on 146.52, what are the two most likely frequencies for the other interfering signal?

146.88 MHz and 146.34 MHz
146.01 MHz and 147.30 MHz
73.35 MHz and 239.40 MHz
146.34 MHz and 146.61 MHz

A-005-06-05 (1)
What type of circuit varies the tuning of an amplifier tank circuit to produce FM signals?

A phase modulator
A balanced modulator
A double balanced mixer
An audio modulator

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A-005-06-06 (3)
What audio shaping network is added at an FM transmitter to attenuate the lower audio frequencies?

An audio prescaler
A heterodyne suppressor
A pre-emphasis network
A de-emphasis network

A-005-06-07 (2)
Which type of filter would be best to use in a 2-metre repeater duplexer?

A DSP filter
A cavity filter
An L-C filter
A crystal filter

A-005-06-08 (1)
The characteristic difference between a phase modulator and a frequency modulator is:

pre-emphasis
the centre frequency
de-emphasis
frequency inversion

A-005-06-09 (4)
In most modern FM transmitters, to produce a better sound, a compressor and a clipper are placed:

between the multiplier and the PA
between the modulator and the oscillator
in the microphone circuit, before the audio amplifier
between the audio amplifier and the modulator

A-005-06-10 (1)
Three important parameters to be verified in an FM transmitter are:

linearity, frequency deviation and frequency stability
distortion, bandwidth and sideband power
modulation, pre-emphasis and carrier suppression
frequency stability, de-emphasis and linearity

A-005-06-11 (2)
For a repeater to operate automatically, the circuit that determines when to turn the transmitter on and off is the:

limiter
carrier operated relay
automatic identifier
multiplier

A-005-07-01 (1)
Maintaining the peak RF output of a SSB transmitter at a relatively constant level requires a circuit called the:

automatic level control (ALC)
automatic gain control (AGC)
automatic output control (AOC)
automatic volume control (AVC)

A-005-07-02 (1)
Speech compression associated with SSB transmission implies:

full amplification of low level signals and reducing or eliminating amplification of high level signals
full amplification of high level signals and reducing or eliminating signals amplification of low level
a lower signal-to-noise ratio
circuit level instability

A-005-07-03 (1)
Which of the following functions Is Not included in a typical digital signal processor?

Aliasing amplifier
Analog to digital converter
Digital to analog converter
Mathematical transform

A-005-07-04 (3)
How many bits are required to provide 256 discrete levels, or a ratio of 256:1?

6 bits
16 bits
8 bits
4 bits

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A-005-07-05 (3)
Adding one bit to the word length, is equivalent to adding ________ dB to the dynamic range of the digitizer:

1 dB
4 dB
6 dB
3 dB

A-005-07-06 (3)
What do you call the circuit which employs an analog to digital converter, a mathematical transform, a digital to analog converter and a low pass filter?

Digital formatter
Mathematical transformer
Digital signal processor
Digital transformer

A-005-07-07 (2)
Which principle Is Not associated with analog signal processing?

compression
frequency division
bandwidth limiting
clipping

A-005-07-08 (2)
Which of the following Is Not a method used for peak limiting, in a signal processor?

RF clipping
frequency clipping
compression
AF clipping

A-005-07-09 (3)
What is the undesirable result of AF clipping in a speech processor?

Reduced average power
Increased average power
Increased harmonic distortion
Reduction in peak amplitude

A-005-07-10 (4)
Which description Is Not correct? You are planning to build a speech processor for your transceiver. Compared to AF clipping, RF clipping:

has less distortion
is more expensive to implement
is more difficult to implement
is easier to implement

A-005-07-11 (1)
Automatic Level Control (ALC) is another name for:

RF compression
AF compression
RF clipping
AF clipping

A-005-08-01 (3)
What digital code consists of elements having unequal length?

AX.25
Baudot
Morse code
ASCII

A-005-08-02 (2)
The International Organization for Standardization has developed a sevenlevel reference model for a packet-radio communications structure. What level is responsible for the actual transmission of data and handshaking signals?

The link layer
The physical layer
The network layer
The transport layer

A-005-08-03 (1)
The International Organization for Standardization has developed a sevenlayer reference model for a packet-radio communications structure. What level arranges the bits into frames and controls data flow?

The link layer
The synchronization layer
The communications layer
The transport layer

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A-005-08-04 (1)
What is one advantage of using ASCII rather than Baudot code?

It is possible to transmit upper and lower case text
ASCII includes built-in error correction
ASCII characters contain fewer information bits
The larger character set allows storeand- forward

A-005-08-05 (3)
What type of error control system is used in AMTOR ARQ (Mode A)?

The receiving station checks the frame check sequence (FCS) against the transmitted FCS
Each character is sent twice
The receiving station automatically requests repeats when needed
Mode A AMTOR does not include an error control system

A-005-08-06 (4)
What error-correction system is used in AMTOR FEC (Mode B)?

Mode B AMTOR does not include an error-correction system
The receiving station automatically requests repeats when needed
The receiving station checks the frame check sequence (FCS) against the transmitted FCS
Each character is sent twice

A-005-08-07 (2)
What is the primary advantage of AMTOR over Baudot RTTY?

Surplus teletype machines that use AMTOR are readily available
AMTOR includes an error detection system
Photographs may be transmitted using AMTOR
AMTOR characters contain fewer information bits than Baudot characters

A-005-08-08 (2)
We have all used the term ASCII when using computers or teletypewriting equipment. What do those initials represent?

A Standard Code for Information Interchange
American Standard Code for Information Interchange
North American System Compatible with International Interchange
Amalgamated System Code for Information Interchange

A-005-08-09 (1)
The designator AX.25 is associated with which amateur radio mode?

packet
RTTY
ASCII
spread spectrum speech

A-005-08-10 (2)
How many information bits are included in the Baudot code?

A-005-08-11 (1)
How many information bits are included in the ASCII code?

A-005-09-01 (1)
What term describes a wide-band communications system in which the RF carrier varies according to some predetermined sequence?

Spread spectrum communication
Amplitude-compandored single sideband
AMTOR
Time domain frequency modulation

A-005-09-02 (4)
What is the term used to describe a spread spectrum communications system where the centre frequency of a conventional carrier is altered many times per second in accordance with a pseudo-random list of channels?

Direct sequence
Time-domain frequency modulation
Frequency compandored spread spectrum
Frequency hopping

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A-005-09-03 (3)
What term is used to describe a spread spectrum communications system in which a very fast binary bit stream is used to shift the phase of an RF carrier?

Frequency hopping
Phase compandored spread spectrum
Direct sequence
Binary phase-shift keying

A-005-09-04 (1)
Frequency hopping is used with which type of transmission?

Spread spectrum
AMTOR
Packet
RTTY

A-005-09-05 (1)
Direct sequence is used with which type of transmission?

Spread spectrum
AMTOR
Packet
RTTY

A-005-09-06 (3)
Which type of signal is used to produce a predetermined alteration in the carrier for spread spectrum communication?

Frequency-compandored sequence
Quantizing noise
Pseudo-random sequence
Random noise sequence

A-005-09-07 (4)
Why is it difficult to monitor a spread spectrum transmission?

It requires narrower bandwidth than most receivers have
It varies too quickly in amplitude
The signal is too distorted for comfortable listening
Your receiver must be frequencysynchronized to the transmitter

A-005-09-08 (3)
What is frequency hopping spread spectrum?

The carrier is amplitude-modulated over a wide range called the spread
The carrier is frequency-compandored
The carrier is altered in accordance with a pseudo-random list of channels
The carrier is phase-shifted by a fast binary bit stream

A-005-09-09 (3)
What is direct-sequence spread spectrum?

The carrier is amplitude modulated over a range called the spread
The carrier is frequency-compandored
The carrier is phase-shifted by a fast binary bit stream
The carrier is altered in accordance with a pseudo-random list of channels

A-005-09-10 (2)
Why are received spread-spectrum signals so resistant to interference?

The receiver is always equipped with a special digital signal processor (DSP) interference filter
Signals not using the spectrum-spreading algorithm are suppressed in the receiver
If interference is detected by the receiver, it will signal the transmitter to change frequencies
The high power used by a spreadspectrum transmitter keeps its signal from being easily overpowered

A-005-09-11 (1)
How does the spread-spectrum technique of frequency hopping (FH) work?

The frequency of an RF carrier is changed very rapidly according to a particular pseudo-random sequence
If interference is detected by the receiver, it will signal the transmitter to change frequency
If interference is detected by the receiver, it will signal the transmitter to wait until the frequency is clear
A pseudo-random bit stream is used to shift the phase of an RF carrier very rapidly in a particular sequence

First